Question 1

A researcher is studying a population of beetles and finds that the frequency of the recessive allele $$a is$$ $$q = 0.3. $$Assuming Hardy-Weinberg equilibrium, what is the expected frequency of heterozygotes in the next generation?

Accepted Answer

$$0.42$$

Question 2

Which of the following best describes the effect of disruptive selection on a population's phenotype distribution and genetic variation?

Accepted Answer

Both extreme phenotypes are favored, resulting in a bimodal distribution and increased genetic variation.

Question 3

A population of lizards is split by the formation of a new river, preventing gene flow between the two groups. Over time, the groups diverge genetically and eventually cannot interbreed even if brought back together. Which type of speciation and sequence of events does this scenario illustrate?

Accepted Answer

Allopatric speciation: geographic barrier → genetic divergence → reproductive isolation

Question 4

Which of the following statements about Hardy-Weinberg equilibrium is CORRECT?

Accepted Answer

It requires that all genotypes have equal fitness, random mating, no mutation, no migration, and a very large population.

Question 5

A mutation in a Drosophila Hox gene causes legs to develop where antennae should be. This is an example of:

Accepted Answer

A homeotic transformation due to altered segment identity

Question 6

Which of the following is a limitation of the Biological Species Concept (BSC)?

Accepted Answer

It cannot be applied to asexual organisms or fossils.

Question 7

In a small population of birds, a rare neutral allele is present at a frequency of $$0.2. $$What is the probability that this allele will eventually become fixed in the population due to genetic drift?

Accepted Answer

$$0.2$$

Question 8

Which of the following best explains why gene flow tends to homogenize populations?

Accepted Answer

It introduces new alleles into populations, making their allele frequencies more similar.

Question 9

A scientist is constructing a phylogenetic tree using DNA sequences. Which principle should they use to choose among possible trees, and why?

Accepted Answer

Choose the tree that requires the fewest evolutionary changes (parsimony), because it is the simplest explanation.

Question 10

Which of the following is an example of heterochrony in evolutionary development?

Accepted Answer

A change in the timing of gene expression, such as giraffe neck vertebrae growing for a longer period.

Question 11

Which of the following best describes the role of mutation in evolution?

Accepted Answer

Mutation is the ultimate source of genetic variation, creating new alleles for selection, drift, and gene flow to act upon.

Question 12

A population of plants undergoes a sudden reduction in size due to a wildfire, leaving only a few survivors. Over time, the genetic diversity of the population is much lower than before. This is an example of:

Accepted Answer

Bottleneck effect

Question 13

Which of the following is a key difference between homologous and homoplastic (convergent) traits when constructing phylogenetic trees?

Accepted Answer

Homologous traits are similar due to shared ancestry, while homoplastic traits are similar due to independent evolution.

Question 14

Which of the following scenarios is most likely to result in sympatric speciation?

Accepted Answer

A plant species undergoes chromosome doubling (polyploidy), creating a new reproductively isolated lineage within the same area.

Question 15

Which of the following is a correct statement about the Cambrian Explosion?

Accepted Answer

It was a period when most major animal body plans appeared rapidly in the fossil record.

Question 16

A population of fish in a lake is found to have more homozygotes and fewer heterozygotes than expected under Hardy-Weinberg equilibrium, but allele frequencies remain unchanged. Which process is most likely responsible?

Accepted Answer

Inbreeding

Question 17

Which of the following best describes reinforcement in the context of speciation?

Accepted Answer

Selection strengthens prezygotic barriers when hybrids have low fitness, accelerating completion of speciation.

Question 18

Which of the following is a valid monophyletic group (clade) in phylogenetic classification?

Accepted Answer

A group that includes an ancestor and all of its descendants.

Question 19

A scientist is using a molecular clock to estimate the divergence time between two mammal species. Which of the following is necessary for accurate calibration of the molecular clock?

Accepted Answer

Fossil evidence providing known ages for calibration points.

Question 20

Which of the following is a real-world example of adaptive radiation?

Accepted Answer

Darwin's finches evolving diverse beak shapes to exploit different food sources in the Galápagos Islands.

Evolution, Development, and the History of Life: Study Notes for BIOL:1411 Final (Lectures 30–40)

Study Guide - Practice Questions

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